Right now, your mind is per­form­ing an aston­ish­ing feat. Photons are boun­cing off these black squiggles and lines – the let­ters in this sen­tence – and col­lid­ing with a thin wall of flesh at the back of your eye­ball. The photons con­tain just enough energy to activ­ate sens­ory neur­ons, each of which is respons­ible for a par­tic­u­lar plot of visu­al space on the page. The end res­ult is that, as you stare at the let­ters, they become more than mere marks on a page. You’ve begun to read.

See­ing the let­ters, of course, is just the start of the read­ing pro­cess. [â€¦] The real won­der is what hap­pens next. Although our eyes are focused on the let­ters, we quickly learn to ignore them. Instead, we per­ceive whole words, chunks of mean­ing. [â€¦] In fact, once we become pro­fi­cient at read­ing, the pre­cise shape of the let­ters – not to men­tion the arbit­rar­i­ness of the spelling – doesn’t even mat­ter, which is why we read word, WORD, and WoRd the same way.